Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the annotations (read-only, idempotent, open-world), the description adds crucial behavioral context: rate-limited, no API key required, the address is not stored, the OFAC list is refreshed daily, and caveats about what a listed/not-listed result means. These details are not available in the structured annotations and materially affect interpretation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core checks and then adds caveats, alternatives, and operational traits in a logical order. It is dense but every sentence carries useful information; minor improvement could come from breaking the long first sentence into a clearer list.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given that an output schema exists, the description need not explain return values. It thoroughly covers what is and is not checked, interpretation caveats, privacy, rate limits, authentication (no API key), and the relevant alternative tool. Nothing essential for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single address parameter is fully documented with example formats (0x…, T…, bc1…/1…/3…, Solana). The description adds little about the parameter itself beyond noting that chain detection comes from the format alone, which is more output semantics than input guidance. Baseline 3 is appropriate when the schema already does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb and resource ('Check one crypto wallet address') and enumerates the exact checks performed: chain inference, checksum validation, OFAC SDN lookup, and phishing-page count. It clearly distinguishes this tool from closely related siblings like crypto_check_before_sign.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly names an alternative ('Use crypto_check_before_sign to judge an address together with the page that asked and the wallet request'), states what this tool does not cover ('Balances, transaction history and the owner are not looked at'), and provides important interpretation guidance for sanctions hits and misses. This gives clear when-to-use and when-not-to-use guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.